The course of fever following influenza virus infection in children treated with oseltamivir

Abstract

Although the effectiveness of oseltamivir against influenza virus infection is well known, there has been no report analyzing the detailed time course of fever following the drug treatment in children. Oseltamivir was prescribed for 4 days to every child with a positive result for rapid immunological test for influenza virus during 2002--2003, 2003--2004, and 2004--2005 epidemics. Only those who were 1-12 years of age and prescribed oseltamivir within 24 hr after the onset of fever were included in the analysis. The numbers of children with type A/H3N2 disease for the three seasons were 64, 77, and 33, and those with type B disease were 102, 4, and 86, for the respective seasons. The period until normalization of temperature was obtained from six-hourly recordings of body temperature. By multiple regression analysis, temperature periods were longer in type B than in type A/H3N2 disease, negatively associated with age, and positively with maximal body temperature (all: P < 0.001). The effectiveness of oseltamivir on body temperature in type B disease was less apparent in the 2004--2005 than in the 2002--2003 season, irrespective of age. No such between-season difference was observed for Type A/H3N2 disease. Frequencies of ineffective cases with biphasic fever (19.6% and 43.0% during 2002--2003 and 2004--2005 seasons) were significantly higher in type B than in type A/H3N disease (12.0% and 11.8%, respectively). The effectiveness of oseltamivir depends on a child's age, maximal body temperature and the virus type. This study confirmed recent reports indicating decreased effectiveness of oseltamivir against type B disease.

Comparison of the clinical effectiveness of zanamivir and laninamivir octanoate for children with influenza A(H3N2) and B in the 2011–2012 season

“…It has been reported that the duration of fever was significantly longer for influenza A and B‐infected patients aged 0–6 years than for those aged 7 years or over when they were treated with amantadine and OT, respectively, and that influenza A or B‐infected patients aged <6 years exhibited prolonged duration of fever when they were treated with OT . It has also been reported that a 1‐year increment in age of patients infected with influenza A or B virus shortened the fever period by 2·4 hours when they were treated with OT . Taken together, the results indicate that duration of fever in patients with influenza tends to be longer in young children than older children when they have been treated with OT.…”

“…Biphasic fever in influenza has been observed in patients with influenza A(H3N2), A(H1N1), and B virus infections who were not administered NAIs and in patients with influenza A(H3N2) and B virus infections who were administered OT . In this study, biphasic fever was observed in 4·3% of the influenza A(H3N2)‐infected patients and in 7·3% of the influenza B‐infected patients (Table ).…”

Oseltamivir for treatment and prophylaxis of influenza infection

“…Two studies from Ontario, Canada, a prospective cohort study of > 500 patients and a case series study evaluating prophylaxis as well as treatment of ∼ 70 patients who received oseltamivir, suggested a decreased likelihood of death [12,[69][70][71][72][73][74][75][76][77]. Other potential benefits of oseltamivir treatment include decreased nasal viral titers, reduced lower respiratory tract complications (i.e., otitis media, bronchitis and pneumonia) with subsequent reduction in antibiotic usage as well as a reduction in length of hospitalization and all-cause hospitalization in Oseltamivir has been shown to be more effective against influenza A than influenza B and when zanamivir was compared to oseltamivir in treatment of influenza B, there was decreased duration of fever and viral persistence with zanamivir [31, [82][83][84][85][86]. A recent pediatric study, however, demonstrated no difference between oseltamivir and zanamivir in reducing febrile periods in children with influenza A (H1N1 and H3N2) and B [87].…”

Experimental Infection of Macaques with a Wild Water Bird-Derived Highly Pathogenic Avian Influenza Virus (H5N1)

“…This biphasic fever was also observed in a cynomolgus monkey after HPAIV inoculation (data not shown). This type of biphasic fever is observed in cases of human influenza [17]. …”